Hearth Steel Swords WIP

[Alan Longmire]

I wouldn't call that a mistake, I'd call it an unintended outcome.

[Aiden CC]

I think the main thing I learned from this is to be extra careful with cleanliness while folding. I forgot to take pictures but I’m working down that material and opted for a cut-and-stack in a few places rather than just folding. I also trimmed off the ragged ends which have been a source of problems in the past. 
 

I loved the feel of that blade and have been wanting to try paying more attention to sword dynamics and design and apply points from @peter johnsson’s work. My goal for this blade is one thing that’s agile but still has some authority, so I opted for a narrower blade with a bit less profile taper. The design below still has some kinks to be worked out, I now see that I need to fix the curve at the tip to be more even. I’m also not sure about the guard length, I may bump it up. The real grip will also need to be narrower. I want to get together about 4 lbs of hearth steel to weld around an iron core for this blade. That should hopefully leave extra that I can cut off to use for other projects. 

 

 

 

[Aiden CC]

I finally had some time to do real work in the shop, and made some progress bringing that blade to life. 
 

I needed more material, so I went though my pile of little scraps and squished all of the highest quality pieces into tiles. A large piece was prepared as a base and the piles were quenched, ground clean, and broken to inspect them. All the best pieces were then stacked and welded. Hearth steel pucks always have uneven composition, and I have found this to be the best way to ensure only the absolute best parts are used. This will be used for the cutting edges. 
 

Now, for the billet, everything is 7 folds. The top is that high quality bar, which consolidated well and maintained good carbon content. Below it are two slightly lower carbon bars (though still definitely hardenable). Not shown is the fact that all the surfaces are ground clean. I welded the bar, drew it out, and folded it so the best material would be in the middle. This billet may look massive, and that’s because it is, being about 6 lbs. After a series of heart breaks with this material, I’ve found the cause is usually trying to save a bit of material. 
 

After that, lots of drawing! This is certainly the largest piece of hearth steel I have ever worked with. It started out as somewhere around 8-10 lbs of wrought iron, two extra large pucks and a similar quantity of little scraps broken off from maybe 5-10 different melts. 
 

I like to weld on wrought iron tangs when possible and thus blade already has enough steel in it if you ask me. I used to do a single sided lap weld, but found this method to be easier and more consistent. 
 

Here’s where it stands now. The blade is 31” long, 2.5” at the base, both will come down by a hair. I also revised the profile taper a bit. The design for this blade started with the feel I want it to have when held, and with this length, I think that would be better served by a pointier blade. I didn’t get a chance to weigh the blade, but I think it will need to lose 30-50% of its weight in grinding. Better than the last one that came out of the forge basically at the target weight!

[Alan Longmire]

Next time I hear someone complain about forging, I'll direct them to this thread.   You're a machine, man!

[Aiden CC]

7 hours ago, Alan Longmire said:

Next time I hear someone complain about forging, I'll direct them to this thread.   You're a machine, man!

Just make sure they aren't complain about grinding, because the pile of half finished blades is what I'm avoiding by doing stuff like this . I blame it on the press. Back when it was all hand forging I would stop when I was too hot and tired to keep going,, now I don't know when to! 

 

To peek behind the curtain, this went from puck to blade in four sessions, following a (fairly flexible) overarching plan. I've found that planning goes a long way when working with material like this, not the least to keep the motivation for the final product alive. The first one, I worked one of the melts up to 3 folds and turned some previously refined material into sanmai bars and then a few knife blades, afterwards working the second large melt up to 1 fold. Second, the 3 fold material was cut and stacked, then brought up to final layer count, and I got all the little pieces welded for the core bar. Third was when everything came together; the 1 fold material was cut and stacked, then refined along with the core bar, everything welded together, then forged into a preform. Finally, was a short session with minor adjustments to the preform and beveling. I was shooting for three originally, but had to quit early to make it to other plans on time.

[Aiden CC]

The big blade made it though heat treatment without any cracks, there are a few “folding scars” here and there, but it’s way better than the last blade. 
You can see a bit of the layering in the scale here. This was a water quench, which was definitely a bit tense. Not shown is a bit more grinding, the blade is down to 810 g. My plan is to not etch this blade, but we’ll see how it goes. 
 

Also, debatably whether it’s a sword, but I did the finish grinding, rough sanding and habaki for this sunobi tanto:

In my opinion the most difficult parts of mounting a Japanese blade, the habaki and saya fit-up are now finished. This blade is made from 12-fold steel wrapped around a wrought iron core, with a deliberately irregular hamon. Once I carve the channel for the tsuka core I’ll polish the blade. I’ve gotten a glimpse of it at the coarse stages of grinding, but I’m excited to see how it comes out in detail. 

[Francis Gastellu]

I find habakis to be incredibly finicky. Getting them to close up "just right" is a challenge that barely gets any easier with practice.

 

You're been doing a lovely job on the big blade in spite of your setbacks (which imho only make it more impressive), can't wait to see it completed!

[Aiden CC]

On 4/21/2023 at 2:08 AM, Francis Gastellu said:

I find habakis to be incredibly finicky. Getting them to close up "just right" is a challenge that barely gets any easier with practice.

 

You're been doing a lovely job on the big blade in spite of your setbacks (which imho only make it more impressive), can't wait to see it completed!

Thank you! I do think it’s telling that there are specialists who primarily make habakis. 
 

Not much progress on these blades, but I did finish the sanding and start the etching process for the tanto:

It still needs a bit more work to get the hamon to pop in more light conditions, but it does come out quite well in the right light. 

[Alan Longmire]

Hada is looking good!

[Aiden CC]

17 hours ago, Alan Longmire said:

Hada is looking good!

Thank you! I'm glad it's starting to come out. The final billet has 128 layers of two alternating steels I had already refined to 6 folds. It seems I always end up with this sort of mokume hada, probably due to how material moves under a press.

[Aiden CC]

It’s been a while, but I ran out of hearth steel from the last run, so time for more! I have some wrought iron sword cores forged out that need edge bars. 
 

Here’s the feedstock, about 25-30 lbs. A number of failed knives and saxes also got thrown in the pot. A bit sad to see them go, but each had an issue I couldn’t solve. Now they can be something new!

 

Here are the results, ten pucks total. I have wrought iron prepared for a double edged sword core to replace the failed one, and a langsax spine as well. 
 

Thanks for looking!

[Joshua States]

15 hours ago, Aiden CC said:

A number of failed knives and saxes also got thrown in the pot.

Oh, how I want to do this!

[Aiden CC]

7 hours ago, Joshua States said:

Oh, how I want to do this!

It was quite cathartic   

 

A better picture of the pucks. From left to right: 1-4: thick, curved wrought plate (giant tire of some kind?), 5: round wrought bars, 6: all the ritually killed knives, 7: some gnarly wrought chain scrap and a failed hearth sanmai bar, 8: wrought iron and refined hearth steel drops and ends, 9: raw heath scraps and wrought iron drops, 10: failed wrought iron knife blanks, with and without hearth steel edges. 
 

I also had an hour and a half today to forge, so I was able to get these two bars (#2 and #3) up to 4 folds. Tomorrow the goal is to produce as much 3/8” square edge bar as possible from them at 7-9 folds, depended on how the behave. If everything goes well, these will have enough for a doubled edged Viking age sword plus a langsax. 

[Joshua States]

Consolidating well it seems. You must have that little hearth working just right.

I envy you your forge time. We are in our 3rd staright week of 110+ degree weather. Turning on the forge, especially at welding heats, is just a no-go for me.

Edited July 23 by Joshua States

[Ryan Hobbs]

On 7/22/2023 at 6:34 PM, Aiden CC said:

It was quite cathartic   

 

A better picture of the pucks. From left to right: 1-4: thick, curved wrought plate (giant tire of some kind?), 5: round wrought bars, 6: all the ritually killed knives, 7: some gnarly wrought chain scrap and a failed hearth sanmai bar, 8: wrought iron and refined hearth steel drops and ends, 9: raw heath scraps and wrought iron drops, 10: failed wrought iron knife blanks, with and without hearth steel edges. 

 

 

Is there a noticeable difference in the way the different pucks perform while forging? Will the different materials involved in each puck make drastic differences or does the hearth steel process level out variables to an  extent?

[Aiden CC]

17 hours ago, Joshua States said:

Consolidating well it seems. You must have that little hearth working just right.

I envy you your forge time. We are in our 3rd staright week of 110+ degree weather. Turning on the forge, especially at welding heats, is just a no-go for me.

It's been hot here, but not that hot! The thermometer in my shop was at 108 F, but only when the forge was running. It may be a while before I run the hearth again, I have a big move coming up and my shop time will go back to being a few bursts per year, so I wanted to get a lot of runs in. This is the most material I've put through in one session, and for the first time, I actually started melting some of the bricks. Somewhat amazingly, I've been able to make all of my steel with the same set of bricks this whole time, this may be a good time for their retirement!

 

14 hours ago, Ryan Hobbs said:

 

 

Is there a noticeable difference in the way the different pucks perform while forging? Will the different materials involved in each puck make drastic differences or does the hearth steel process level out variables to an  extent?

The main difference during forging comes down to how well they consolidated in the hearth (and then only up to the first 1-2 folds), with a few exceptions. I try to get 10-20 lbs of a feedstock at a minimum, the main reason I keep track is to see if a batch has poor carbon uptake (likely P), hot shortness (probably, Cu or S), etc. That, along with the experience of others here with them, is why I stopped using Globe Elevator nails, for example.

[Aiden CC]

Two more forging sessions and something is starting to come together. 
 

Here are the two edge bars from that billet. They are both hardenable, but have different carbon contents (maybe 0.6 for one and 0.8 for the other). I decided they probably wouldn’t play nice as the two edges on the same blade, so one will become a single edged blade, and the second will wait for a buddy to become a double edged sword. 

Speaking of single edged blades… if everything goes right, this will become a single edged Viking age sword. The blade is currently 71 cm, I think I can bump that up closed to 75 with a bit more forging, which was my original goal. It also still needs a wrought tang welded on, so hopefully one more session and this will be done. The watering can in the background was to wet down the floor, my shop thermometer said it was 113 F once the forge was running! At least it’s a dry heat 
 

I forgot pictures, but this afternoon I also processed another puck which now just needs to be drawn out to 3/8” square to join up with that other bar. My second sword core turned out to be some kind of old fashioned mild steel instead of wrought (I found out from my KITH knife), so I’ll also need to break down some more anchor chain too. I think the single edged sword will be a good stepping stone before I work on some double edged blades (I haven’t forgotten about the later medieval sword, don’t worry!).